Streetlight Voltage Drop Calculator

If you're an electrician or contractor, you can check the voltage of streetlights.

This calculation uses only 2 x #4AL conductor. If you need a bigger conductor, contact the design lead on your turnkey documents.

Ready to Get Started?

Calculator row 1 — Start with the streetlight that’s located farthest from the source. Enter the number of lamps on that standard. Then the distance to the next standard.

Other rows — Now, work backwards towards the source. Enter the number of lamps on each standard. Then enter the distance of the next streetlight standards. On the last row, enter the number of lamps closest to the source. Then the distance between that standard and the source.

If the service pedestal is a source — Use the Residential Voltage Drop Calculator. This will help you figure out the voltage drop from the transformer to the pedestal. Add that result to the calculated streetlight voltage drop total.

Please note: The sec cable length you enter must include cable snaking and vertical bends.

Note: The highest total voltage drop from the first transformer to the farthest streetlamp is 8%. This calculation’s based on 120-volts.